cam gears

[keo92stealth]

Are adjustable cam gears needed when the heads have been decked ? Ive read this before somewhere .

[DK77]

I have heard that as well. In order to truly have the cams in perfect time, you have to degree the cams once it's put together and adjust the gears accordingly. That said, with everything stock your cams probably won't be off enough to tell a difference.

[TurboSinceBirth]

It depends how much they've been resurfaced. I had a set of heads that were off about 3 degrees on the intake and exhaust side because of being rebuilt about 3 different times. For my 500AWHP setup I probably would have lost about 30-40AWHP by not adjusting the timing back to stock using the adjustable cam gears. It can make a difference but unless there has been quite a bit of material taken off or you can see the cam gears are off a 1/2 a tooth I wouldn't worry about it with stock cams.

[keo92stealth]

Yea I'm just gonna run stock ones for now . Sold my 280s. These heads have been surfaced to the max. They can't be decked anymore . It will then cut the water or coolant jackets .

So even with the timing marks lined up its still gonna be off??

[AdamVR4]

I have heard that as well. In order to truly have the cams in perfect time, you have to degree the cams once it's put together and adjust the gears accordingly. That said, with everything stock your cams probably won't be off enough to tell a difference.

My heads were decked in 2004. Stock cam gears... I do have to run more boost than some e16g cars but im ok with that

[keo92stealth]

My heads were decked in 2004. Stock cam gears... I do have to run more boost than some e16g cars but im ok with that

I was wondering why you ran so much boost adam when you made the 585awhp . Thought it would have made 600 plus at 30 plus pounds .

[TurboSinceBirth]

Yea I'm just gonna run stock ones for now . Sold my 280s. These heads have been surfaced to the max. They can't be decked anymore . It will then cut the water or coolant jackets .

So even with the timing marks lined up its still gonna be off??

Yep. Mine was. Unless you're trying to get the last 10% out of your setup you shouldn't worry about it. You'll know when you put the motor together with the timing marks lined up but the teeth on the belt not lining up. It just won't perform at it's peak potential and is probably more of a problem at higher boost. I wish I had before/after dyno numbers to know for sure what the difference is.

[AdamVR4]

I was wondering why you ran so much boost adam when you made the 585awhp . Thought it would have made 600 plus at 30 plus pounds .

The highly unrefined tune and less than ideal octane and hot lapping on dyno and potentially low compression and lack of meth/alky/any injection all contribute ...lol... but yeah.

[ChargerX3]

I had to deck mine again and i didnt have any timing issues. Everything lined up well. I can probably only deck them one more time.

[RealMcCoy]

I'll quote myself from the last time I addressed this:

As far as the original question of how much will deck height changes effect cam timing? It's pretty easy math provided you make a couple "close enough" assumptions.

We know that each tooth on the belt is 15 crankshaft degrees(7.5 cam degrees) if we assume that each time the belt crosses the head gasket surface it is lengthened by the reduction in deck height,(I say assume because there are some angles involved. they're not severe, so without breaking out the trig, we'll call it close enough for government work...) and we assume that my measurement of .280 for the distance of a belt tooth is pretty close, we can do a couple quick calculations.

First we go after our multiplier(we're using the OP's .030" figure as an example): .030/.280= .107 Then we can use our multiplier to figure out how much each belt crossing effects the cams: 7.5X.107= .8deg

So the rear cams will be off a little less than 1 degree because the belt only crosses the gasket plane once before turning the cams. The front cams are not so lucky, the belt crosses the gasket plane three times before turning them, so your front cams will be off almost 2.5 degrees.